1. FIELD OF THE INVENTION
The present invention relates to electrical couplings between the wiring systems of tractor and trailer vehicles.
2. DESCRIPTION OF RELATED ART
When technology advances in an area where electrical power is used, the electrical power demands of that field often also increase. For example, lighting demands in the trucking industry have been steadily rising. The increased demand for lighting on a tractor vehicle and a trailer vehicle causes a concomitant increase in demand on the electrical power of the towing vehicle. However, because electrical circuits have a power handling capacity, as the electrical power demands of an electrical circuit are increased, the risk of exceeding the power capacity of that circuit grows. Thus, there is a potential problem with the power handling capacity of the electrical circuits between tractor and trailer vehicles being exceeded.
Such demands have caused the standard configuration of electrical connectors for use between tractor and trailer vehicles to change a few times. When six electrical terminals became a standard in the trucking industry, the typical wiring harnesses between tractor and trailer vehicles became arranged in a circular configuration because a circular configuration conserves space for electrical harnesses containing six or more terminals. The current standard electrical connection for electrical harnesses connecting tractor and trailer vehicles in the trucking industry is a connection consisting of a central electrical terminal (for attachment of auxiliary electrical components) surrounded by six radially disposed equidistant electrical terminals forming a circle, i.e. a "seven-way" connection.
The following U.S. Patents each show connections for the current standard seven-way electrical connection: U.S. Pat. No. 4,061,407, issued to John P. Snow on Dec. 6, 1977; U.S. Pat. No. 4,770,644, issued to Emil Feder on Sep. 13, 1988; U.S. Pat. No. 4,792,308, issued to Raymond L. Johnson on Dec. 20, 1988; U.S. Pat. No. 5,080,594, issued to Stephen W. Swinford on Jan. 14, 1992; U.S. Pat. No. 5,385,476, issued to Kenneth O. Jasper on Jan. 31, 1995; U.S. Pat. No. 5,514,009, issued to Michael T. Hughes on May 7, 1996; and U.S. Pat. No. 5,516,136, issued to Peter L. Matthews et al. on May 14, 1996.
As noted, the number of terminals in the standard seven-way connection for a wiring harness electrically interconnecting the electrical systems of tractor and trailer vehicles has increased over time. The following patents show electrical connections for electrical wiring harnesses electrically interconnecting tractor and trailer vehicles in the trucking industry different from those of the current standard: U.S. Pat. No. 2,660,679, issued to Arthur E. Hunt on Nov. 24, 1953; U.S. Pat. No. 4,460,811, issued to Paul G. Murr et al. on Jul. 17, 1984; U.S. Pat. No. 4,781,393, issued to C. Duane Jeter on Nov. 1, 1988; U.S. Pat. No. 4,842,532, issued to Jeffrey J. Krause on Jun. 27, 1989; U.S. Pat. No. 5,443,389, issued to Michael T. Hughes on Aug. 22, 1995; German Patent Number 3,904,522, published on Aug. 16, 1990; and European Patent Number 610,681, published on Aug. 17, 1994.
Furthermore, changes in the standard connection for a wiring harness electrically interconnecting the electrical systems of tractor and trailer vehicles take place gradually, because tractor and trailer vehicles which were complementarily constructed and compatible with a previous standard remain on the road for many years after a change occurs in the manufacturing standard. Thus, because tractors and trailers are intended to be used interchangeably, the need for adapters capable of electrically interconnecting otherwise incompatible electrical connections arise as new lighting devices, or other electrically operated devices, are added to one or the other. The following U.S. Patents show adapters capable of electrically interconnecting otherwise incompatible electrical connections between tractor and trailer vehicles: Hughes '389, Hughes '009, Jeter '393, and Krause '532.
However, none of the above inventions and patents show an electrical wiring harness having an eight pronged electrical connection consisting of a central auxiliary terminal surrounded by seven radially disposed equidistant terminals arranged in a circular configuration for use between tractor and trailer vehicles having a standard seven-way connection. Likewise, none of the above inventions and patents show an adapter capable of electrically interconnecting the current standard configuration of electrical terminals in a wiring harness between tractor and trailer vehicles with an eight pronged electrical connection consisting of a central auxiliary terminal surrounded by seven radially disposed equidistant terminals arranged in a circular configuration. Thus, none of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Therefore, an eight-way electrical coupling system for tractor and trailer vehicles solving the aforementioned problems is desired.